Meta

Purpose Insulin-like growth factors (IGFs) regulate a wide range of biological functions including cell proliferation, differentiation, and apoptosis through paracrine and autocrine mechanisms. survival rates were 69.9% and 86.7%, respectively. In a multivariate analysis including age, gender, primary site of disease, pathology, and risk stratification, no significant association was observed between the polymorphism of the and genes and survival. Conclusion None of the five and gene polymorphisms investigated in this study was found to be an independent prognostic marker for Korean patients with surgically resected GIST. However, further studies on a larger scale are warranted to clarify the role of and gene polymorphisms as a prognostic biomarker for GIST patients. and family has also been shown to be correlated with a poor prognosis for GISTs [10]. In addition, epidemiologic studies have indicated that high plasma plays a role in energy balance, which has also been shown to influence risk for solid tumors including GIST [11]. Thus, given these results, IGF or its family would seem to play an important role in tumor growth and spread, thereby affecting the prognosis for GISTs. Single nucleotide polymorphisms (SNPs) have already been widely implicated in cancer development, prognosis, and treatment response, yet similar evidence is usually lacking for genes. Although IGF-1 tag SNPs have been associated with circulating IGF-1 levels, the functional polymorphisms that might be mediating these associations have not been identified [12]. Wong et al. [13] reported that a putative regulatory IGF-1 in the promoter region is associated with reduced colorectal cancer risk. In addition, IGF-1 haplotype and the IGF2 Ex4-233 C/T polymorphism was also found to be significantly associated with risk of pancreatic cancer [14]. To date, only a few studies have been published in regards with the relationship between the SNP of IGF or its family gene and clinical outcomes of GISTs. Therefore, the present study analyzed five and gene polymorphisms and their effect on the prognosis for GIST patients. METHODS Study populace All the tissues investigated in this study were obtained from 213 consecutive Korean patients who underwent surgical resection between January 1998 and June 2008 at five medical centers. The GIST risk A-674563 stratification was classified according to the National Institutes of Health (NIH) consensus classification system [7]. Retrospective information was also received concerning the patient characteristics and the date of A-674563 diagnosis, Rabbit Polyclonal to Stefin B relapse, and death. Written informed consent for gene expression analyses was received from the patients, and the study was approved by the Institutional Review Board at Kyungpook National University Hospital (KNUH). Selection of target IGF-1/2 gene polymorphisms Due to high number of SNPs in the human genome, the initial challenge was the efficient selection of the SNPs most likely to contribute phenotypic effects. Thus, a prioritizing strategy was created using public databases that provide diverse information on the potential phenotypic risks of SNPs. A-674563 First candidate genes involved in IGF and related information were collected from web-based databases that included information on the biologic pathway and potential biologic effects of polymorphisms. Next, SNPs with frequencies lower than 0.1 were excluded based on the allele frequencies recorded for East Asian populations obtained from FASTSNP (function analysis and selection tool for SNP). The selected SNPs were then scored according to certain phenotypic risks and ordered according to A-674563 the sum of risk scores based on the algorithm suggested in a previous report [15]. Finally, and four IGF-1 (+2995C/A, +533C/T, IVS2-16540A/G, Ex4-177G/C) and one IGF-2 (IVS1+1280A/G) gene polymorphisms were included in the current analysis. Genotyping of IGF-1 and IGF-2 gene polymorphisms The genomic DNA was extracted from paraffin-embedded tissue, and four (+2995C/A, +533C/T, IVS2-16540A/G, Ex4-177G/C) and one (IVS1+1280A/G) gene polymorphisms were determined using a Sequenom MassARRAY system. The genotyping was undertaken using the Sequenom iPLEX platform, according to the manufacturer’s instructions (www.sequenom.com; Sequenom Inc., San Diego, CA, USA). The detection of SNPs was carried out by analyzing the primer extension products generated from previously amplified genomic DNA using a Sequenom chip-based matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry platform. Multiplex SNP assays were designed using SpectroDESIGNER ver. 2.06 (Sequenom Inc.). The PCR amplification took place in a 5 L mixture made up of 10 ng genomic DNA, 100 nM of each amplification primer, 500 mM dNTP mix, 1.625 mM MgCl2, and 5.5 units of HotStarTaq DNA Polymerase (Qiagen, Hilden, Germany). The mixture was subjected to the following PCR conditions: a single denaturation cycle at 95 for 15 minutes, followed by 45 cycles at 94 for 20 seconds, 56 for 30 seconds, 72 for 60 seconds, and a final extension at 72 for 3 minutes. Any unincorporated nucleotides in the PCR product were deactivated using shrimp alkaline phosphatase. The allele discrimination reactions were conducted by adding allele-specific extension primers, DNA polymerase, and a cocktail mixture of deoxynucleotide triphosphates and di-deoxynucleotide triphosphates to each well. MassEXTEND clean resin.